Skip to main content

Research Repository

Advanced Search

Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations

Zavala, Jorge A.; Buat, Véronique; Casey, Caitlin M.; Finkelstein, Steven L.; Burgarella, Denis; Bagley, Micaela B.; Ciesla, Laure; Daddi, Emanuele; Dickinson, Mark; Ferguson, Henry C.; Franco, Maximilien; Jiménez-Andrade, E.F.; Kartaltepe, Jeyhan S.; Koekemoer, Anton M.; Le Bail, Aurélien; Murphy, E.J.; Papovich, Casey; Tacchella, Sandro; Wilkins, Stephen M.; Aretxaga, Itziar; Behroozi, Peter; Champagne, Jaclyn B.; Fontana, Adriano; Giavalisco, Mauro; Grazian, Andrea; Grogin, Norman A.; Kewley, Lisa J.; Kocevski, Dale D.; Kirkpatrick, Allison; Lotz, Jennifer M.; Pentericci, Laura; Pérez-González, Pablo G.; Pirzkal, Nor; Ravindranath, Swara; Somerville, Rachel S.; Trump, Jonathan R.; Yang, Guang; Aaron Yung, L.Y.; Almaini, Omar; Amorín, Ricardo O.; Annunziatella, Marianna; Arrabal Haro, Pablo; Backhaus, Bren E.; Barro, Guillermo; Bell, Eric F.; Bhatawdekar, Rachana; Bisigello, Laura; Buitrago, Fernando; Calabrò, Antonello; Castellano, Marco; Chávez Ortiz, Óscar A.; Chworowsky, Katherin...

Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations Thumbnail


Jorge A. Zavala

Véronique Buat

Caitlin M. Casey

Steven L. Finkelstein

Denis Burgarella

Micaela B. Bagley

Laure Ciesla

Emanuele Daddi

Mark Dickinson

Henry C. Ferguson

Maximilien Franco

E.F. Jiménez-Andrade

Jeyhan S. Kartaltepe

Anton M. Koekemoer

Aurélien Le Bail

E.J. Murphy

Casey Papovich

Sandro Tacchella

Stephen M. Wilkins

Itziar Aretxaga

Peter Behroozi

Jaclyn B. Champagne

Adriano Fontana

Mauro Giavalisco

Andrea Grazian

Norman A. Grogin

Lisa J. Kewley

Dale D. Kocevski

Allison Kirkpatrick

Jennifer M. Lotz

Laura Pentericci

Pablo G. Pérez-González

Nor Pirzkal

Swara Ravindranath

Rachel S. Somerville

Jonathan R. Trump

Guang Yang

L.Y. Aaron Yung

Professor of Astrophysics

Ricardo O. Amorín

Marianna Annunziatella

Pablo Arrabal Haro

Bren E. Backhaus

Guillermo Barro

Eric F. Bell

Rachana Bhatawdekar

Laura Bisigello

Fernando Buitrago

Antonello Calabrò

Marco Castellano

Óscar A. Chávez Ortiz

Katherine Chworowsky

Nikko J. Cleri

Seth H. Cohen

Justin W. Cole

Kevin C. Cooke

M.C. Cooper

Asantha R. Cooray

Luca Costantin

Isabella G. Cox

Darren Croton

Romeel Davé

Alexander de la Vega

Avishai Dekel

David Elbaz

Vicente Estrada-Carpenter

Vital Fernández

Keely D. Finkelstein

Jonathan Freundlich

Seiji Fujimoto

Ángela García-Argumánez

Jonathan P. Gardner

Eric Gawiser

Carlos Gómez-Guijarro

Yuchen Guo

Timothy S. Hamilton

Nimish P. Hathi

Benne W. Holwerda

Michaela Hirschmann

Marc Huertas-Company

Taylor A. Hutchison

Kartheik G. Iyer

Anne E. Jaskot

Saurabh W. Jha

Shardha Jogee

Stéphanie Juneau

Intae Jung

Susan A. Kassin

Peter Kurczynski

Rebecca L. Larson

Gene C.K. Leung

Arianna S. Long

Ray A. Lucas

Benjamin Magnelli

Kameswara Bharadwaj Mantha

Jasleen Matharu

Elizabeth J. McGrath

Daniel H. McIntosh

Aubrey Medrano

Emiliano Merlin

Bahram Mobasher

Alexa M. Morales

Jeffrey A. Newman

David C. Nicholls

Viraj Pandya

Marc Rafelski

Kaila Ronayne

Caitlin Rose

Russell E. Ryan Jr.

Paola Santini

Lise-Marie Seillé

Ekta A. Shah

Lu Shen

Raymond C. Simons

Gregory F. Snyder

Elizabeth R. Stanway

Amber N. Straughn

Harry I. Teplitz

Brittany N. Vanderhoof

Jesús Vega-Ferrero

Weichen Wang

Benjamin J. Weiner

Christopher N.A. Willmer A.

Stijn Wuyts


Lyman-break galaxy (LBG) candidates at z ≳ 10 are rapidly being identified in James Webb Space Telescope (JWST)/NIRCam observations. Due to the (redshifted) break produced by neutral hydrogen absorption of rest-frame UV photons, these sources are expected to drop out in the bluer filters while being well detected in redder filters. However, here we show that dust-enshrouded star-forming galaxies at lower redshifts (z ≲ 7) may also mimic the near-infrared (near-IR) colors of z > 10 LBGs, representing potential contaminants in LBG candidate samples. First, we analyze CEERS-DSFG-1, a NIRCam dropout undetected in the F115W and F150W filters but detected at longer wavelengths. Combining the JWST data with (sub)millimeter constraints, including deep NOEMA interferometric observations, we show that this source is a dusty star-forming galaxy (DSFG) at z ≈ 5.1. We also present a tentative 2.6σ SCUBA-2 detection at 850 μm around a recently identified z ≈ 16 LBG candidate in the same field and show that, if the emission is real and associated with this candidate, the available photometry is consistent with a z ∼ 5 dusty galaxy with strong nebular emission lines despite its blue near-IR colors. Further observations on this candidate are imperative to mitigate the low confidence of this tentative submillimeter emission and its positional uncertainty. Our analysis shows that robust (sub)millimeter detections of NIRCam dropout galaxies likely imply z ∼ 4-6 redshift solutions, where the observed near-IR break would be the result of a strong rest-frame optical Balmer break combined with high dust attenuation and strong nebular line emission, rather than the rest-frame UV Lyman break. This provides evidence that DSFGs may contaminate searches for ultra-high redshift LBG candidates from JWST observations.


Zavala, J. A., Buat, V., Casey, C. M., Finkelstein, S. L., Burgarella, D., Bagley, M. B., …Wuyts, S. (2023). Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations. Astrophysical Journal Letters, 943(2), Article L9.

Journal Article Type Article
Acceptance Date Dec 14, 2022
Online Publication Date Jan 25, 2023
Publication Date Feb 1, 2023
Deposit Date Dec 19, 2022
Publicly Available Date Jan 25, 2023
Journal Astrophysical Journal Letters
Print ISSN 2041-8213
Electronic ISSN 2041-8213
Peer Reviewed Peer Reviewed
Volume 943
Issue 2
Article Number L9
Keywords Space and Planetary Science; Astronomy and Astrophysics
Public URL
Publisher URL


You might also like

Downloadable Citations